SHELLS WITHOUT CANALS 



199 



The shell in question is an inch or more in length, 

 and consists oi about ten strongly ribbed whorls. 

 The outside is dull and black, but the inside is of a 

 glossy brown. The aperture is entire, that is, it has 

 no canal, and it is closed by a thin, brown, circular 

 operculum. This species extends at least as far 

 south as San Diego. There are several varieties, 

 differing somewhat from typical shells, one of which, 

 var. pullata, Gould, is heavily ribbed; another, var. 

 hyporhyssa. Berry, is unusually smooth and tapering. 



'^ rich otro pis horealis^ Br. & Sby., the Northern 

 Hairy-shell. This species has a short spire, strongly 

 shouldered whorls which are hairy on the ridges, and 

 a distinct umbilicus. There are many varieties, but 

 the average length is about one inch. This species 

 inhabits the Arctic waters on both sides of the 

 continent. 



'^richotropis cancellata^ Hinds, the Checked 

 Hairy-shell, has a longer spire than that of the last 

 species, consisting of about seven whorls. The epi- 

 dermis, which is somewhat hairy, is light brown or 

 grayish, and the aperture is 

 often pink. It ranges from 

 Alaska southward to Vancou- 

 ver Island, where it is said to 

 occur abundantly. 



Figure 192 shows us an en- 

 larged view ot Anaplocamus 

 borealis^ Dall, the Northern 

 Anaplocamus. This singular 

 shell, which much resembles 

 some that live in fresh water, Fig. 192 



